Reportable Segments (Schedule of Capital Expenditures) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Capital expenditures	$ 260	$ 177	$ 214
IMTT
Segment Reporting Information [Line Items]
Capital expenditures	176	63	74
Atlantic Aviation
Segment Reporting Information [Line Items]
Capital expenditures	61	67	82
MIC Hawaii
Segment Reporting Information [Line Items]
Capital expenditures	20	23	29
Corporate and Other
Segment Reporting Information [Line Items]
Capital expenditures	$ 3	$ 24	$ 29